Meanwhile, some probabilistic approaches were also proposed for the scaling registration of partially overlapping point sets. By representing range images by Gaussian mixture models (GMMs), Myronenko and Song [1]} considered the alignment of two range images as a probability density estimation problem, which can be solved by iteratively fitting the
GMM centroids with EM algorithm. In [2]}, range images are also represented as GMMs, then the registration
problem is viewed as that of aligning two Gaussian mixtures by minimizing their discrepancy. Although these probabilistic approaches are very accurate, they are always requiring huge computational resources. Recently, Du et al. [3]} combined the ICP algorithm with EM algorithm to achieve the scaling registration. It also needs to estimate boundaries of the scale factor. Therefore, a more effective approach is required to be proposed for the scaling registration of point sets.
